The Irish marriage equality referendum on 22 May is a truly historic moment. For an island once considered the last vanguard of the Vatican, this is a seminal moment. Polls indicate high levels of support , and every political party bar none is advocating a vote for marriage equality. This is an incredible shift for a country that only decriminalised homosexuality as recently as 1993 . Yet the last remnants of Catholic Ireland die hard, and a predictable war of words has erupted, with some considerable abuse of research used to bolster bad arguments.

Catholic think-tank the Iona Institute are amongst the loudest voices on the no side. Along with other no campaigners, their main argument has been a rather cynical attempt to reframe the referendum as about children rather than marriage equality, a misconception the referendum commissioner has taken pains to dismantle. This hasn’t discouraged Iona and their fellow no campaigners from attempting to emotively and dishonestly reframe the discussion, however.

This perhaps isn’t surprising - religious conservatives have a long and ignoble history of distorting research to fit their religious ethos, dressing up their biases with the veneer of science. Yet as I’ve written before for the Irish Times and elsewhere , these assertions are fundamentally false and belie an extremely devious attitude to research. Their conduct as the referendum looms is the same nonsense they have long asserted.

Iona leader David Quinn spoke against gay marriage in front of the constitutional committee a number of years ago, arguing against holding a referendum. Ostensibly citing research from Child Trends, Quinn claimed that children fared best with biological parents, and that same-sex parents were inferior for children. Such manoeuvres reveal Quinn is either utterly ignorant about how to read a research paper or quite happy to distort evidence: the first page of the study he quotes makes this abundantly clear: “... neither same-sex parents nor adoptive parents were identified ... therefore, no conclusions can be drawn from this research about the wellbeing of children raised by same-sex parents or adoptive parents.”

Of course, if Quinn and his colleagues gave a damn about the reality of the situation, they would have found their protestations on the suitability of same-sex parents to be utterly misplaced. Numerous studies have since found precisely zero differences in parenting or child outcomes between same-sex or opposite sex couples. The American psychological association state rather succinctly that “... the evidence to date suggests that home environments provided by lesbian and gay parents are as likely as those provided by heterosexual parents to support and enable children’s psychosocial growth.”.

Sadly, the insinuation that same-sex parents are defective continues unabated. Fellow Iona patron Professor Patricia Casey was publicly rebuked on two separate occasions last year for misusing research from both Uppsala University and UNICEF to reach the same dubious conclusion, prompting UNICEF Ireland’s executive director Melanie Verwoerd to slam Casey’s spin as “incorrect and unacceptable”.

Casting aspersions on same-sex parents is far from unique to Ireland. A 2013 paper by Professor Mark Regenus implying deficiencies in same-sex parents was championed by conservative organisations worldwide, despite being academically savaged. Similar pronouncements last year by Professor Douglas Allen have been equally enthusiastically trumpeted, despite being similarly tarnished. Allen and Regenus are members of the National Organisation for Marriage, a political organisation dedicated to opposing gay marriage and adoption. As Prof. Darren Sherkat notes “... there should be reflection about a conservative scholar garnering a very large grant from exceptionally conservative foundations to make incendiary arguments about the worthiness of LGBT parents”. Thus, when religious conservatives parrot these empty claims, extreme scepticism should be the default position.

The suitability of same-sex parenting aside, it should also be noted that the entire issue is a red herring. The constitutional change, if enacted, will simply extend marriage equality to same-sex couples: adoption and surrogacy laws are completely unaffected and it is vapid in the extreme to invoke them.

Even the flimsy pretext of concern for children rings resoundingly hollow: despite the odious insinuations of conservative groups, homosexuality itself is not psychologically unhealthy. It is true that non-heterosexual youths suffer proportionally higher depression rates than their heterosexual counterparts, but this difference is correlated heavily to homophobic treatment by peers and, worse again, parental disapproval. A 2009 study found that children who experienced a high level of parental rejection of their sexuality were six times as likely to be depressed and eight times as likely to have attempted suicide, relative to youths whose sexuality was accepted by their parents. Other studies have indicated that when homophobic abuse wasn’t a factor, homosexual students are psychologically indistinguishable from heterosexual students.

While religious conservatives wring their hands in a gesture of concern, the black irony of the whole debacle is that their pathological fixation on sexuality stigmatises the very youth they ostensibly care for. The no campaign, whatever its intention, has reiterated the ugly fiction that homosexual relationships are inherently inferior to their heterosexual counterparts. This influence on public discussion has been nothing short of malignant, resorting to emotional blackmail and transparent scaremongering – ugly implications as false as they are cruel. The implicit homophobia underlying these messages sends an alarming signal to any astute observer that homosexuality is simply not normal and homosexuals do not have any place with children.

Finally, some on the no side have attempted to frame their side as somehow defending marriage. But given that same-sex marriage will not change the status of traditional marriage, this is easily dismissed. These arguments hinge on the rather ropey and profoundly Catholic notion that marriage exists solely as a vehicle for procreation. It’s a somewhat archaic view contradicted by the fact that many married couples choose not to have children, and many children are born outside marriage. In any case, marriage is a civil issue and no religion, even Irish Catholicism, can honestly lay claim to it.

So far, Irish polls predict a comfortable win for the yes side, leading to the world’s first enactment of same-sex marriage by popular vote. While this is encouraging, history – and statistics – warn us we cannot be that complacent. In 1995, the Irish divorce referendum was passed by a hair’s breadth, with a margin of less than 1%, despite polls beforehand predicting it would pass easily.

This may be due to a phenomenon known by pollsters as Shy Tory factor: some people, when polled, will state a voting intention considered more socially acceptable to the poll-taker, but cast a conflicting one in the privacy of the voting booth. Given it is quite rightly frowned upon to be openly homophobic in 2015, this is certainly a concern in this referendum.

The other big factor is turnout: when turnout is low, only those strongly invested in a particular outcome will vote, and this can skew the result to something quite at odds with majority opinion – essentially a selective sampling problem. This may have been the case in Seanad abolition referendum in 2013, when a turnout of less than 40% skewed the result to quite the opposite of polling predictions.

Ultimately, campaigners in both camps are aware it will be turnout that decides the election. While I generally attempt to hold a neutral position on the pieces I write, I feel obliged to declare an interest here, having canvassed for a yes vote in Ireland last week. As an Irish expatriate living abroad, I cannot vote, yet dearly hope it passes and Ireland becomes a more equal place. Regardless of one’s voting intention, the scaremongering from the no side is simply so much sound and fury, and should be dismissed with the contempt it deserves. Their ostensible grasps at scientific credibility crumble upon even a cursory inspection, and their odious arguments, bereft of facts, should not be allowed set the tone of the conversation.

For those with the privilege of voting in such an historic day, I implore you not to let apathy rule, and to use your vote so we can be proud of the country we all call home.